Sensor for measuring wind angle

Abstract

A differential pressure-induced airflow based approach is used to measure Angle-Of-Attack (AOA) or Angle-Of-Sideslip (AOS) for an aircraft. Ports on opposing sides of an aircraft fuselage are coupled by an airway incorporating a mass airflow sensor. As the relative wind's angle of incidence changes direction with respect to the aircraft's longitudinal axis or wing chord, a differential pressure is created. The differential pressure induces an airflow between the ports whose magnitude is measured by a mass airflow sensor. The resulting airflow is a function of the respective AOA or AOS. The measured airflow and air data computer supplied parameters of airspeed (or dynamic pressure) and altitude (or static pressure) are utilized by an algorithm that reduces the data into angular AOA or AOS measurements.

What is claimed is:  
     
       1. An aircraft comprising: 
       a first port positioned on a first side of the aircraft's fuselage;  
       a second port positioned on a second side of the aircraft's fuselage;  
       a pneumatic passage interconnecting the two ports; and  
       a mass airflow sensor positioned in the passage interconnecting the ports.  
     
     
       2. The aircraft of  claim 1  wherein the first and second ports comprise subassemblies mounted substantially flush with the aircraft, wherein the ports comprise one or more orifices. 
     
     
       3. The aircraft of  claim 1  wherein the airflow sensor comprises a thin film mass airflow sensor. 
     
     
       4. The aircraft of  claim 1  wherein the first and second ports substantially mirror each other on opposite sides of the aircraft in either a port-starboard or top-bottom arrangement. 
     
     
       5. The aircraft of  claim 4  wherein the first and second ports are located proximate the front of the aircraft. 
     
     
       6. The aircraft of  claim 1  wherein the pneumatic passage comprises a tube or other pneumatic plumbing between the first and second ports. 
     
     
       7. The aircraft of  claim 6  wherein the pneumatic passage follows the contour of the aircraft. 
     
     
       8. The aircraft of  claim 6  wherein the pneumatic passage follows a substantially direct line between the first and second ports. 
     
     
       9. A portion of an aircraft comprising: 
       means for conveying airflow between a first port on a first surface of the nose section and a second port on a second surface of the nose section; and  
       means for sensing airflow between the ports.  
     
     
       10. The portion of the aircraft of  claim 9  wherein the first and second ports comprise subassemblies mounted substantially flush with the aircraft, wherein the subassemblies comprise one or more orifices and an integral plenum connecting the orifices in each individual port. 
     
     
       11. The portion of the aircraft of  claim 10  wherein the means for sensing airflow comprises a thin film mass airflow sensor. 
     
     
       12. The aircraft of  claim 10  wherein the pneumatic passage comprises a tube or other pneumatic plumbing between the first and second ports. 
     
     
       13. The aircraft of  claim 12  wherein the pneumatic passage follows the contour of the aircraft. 
     
     
       14. The aircraft of  claim 12  wherein the pneumatic passage follows a substantially direct line between the first and second ports. 
     
     
       15. The portion of the aircraft of  claim 10  wherein the first and second ports substantially mirror each other on opposite surfaces of the portion of aircraft. 
     
     
       16. The portion of the aircraft of  claim 15  wherein the first and second ports are located proximate the front of the aircraft. 
     
     
       17. The portion of the aircraft of  claim 16  wherein the first and second ports are located on a wing or tail of the aircraft. 
     
     
       18. A method of measuring the angle of wind with respect to an aircraft, the method comprising: 
       allowing airflow from one side to an opposite side of a fuselage of the aircraft wherein the airflow is through the fuselage; and  
       measuring the rate of such airflow.  
     
     
       19. The method of  claim 18  and further comprising utilization of the airspeed or dynamic pressure and altitude or static pressure data. 
     
     
       20. The method of  claim 18  wherein allowing airflow comprises: 
       installing ports that have an installation orientation with substantially opposing normal-surface vectors on the aircraft; and  
       coupling the ports with pneumatic plumbing.  
     
     
       21. The method of  claim 20  wherein airflow is measured with an airflow sensor incorporated in the pneumatic plumbing. 
     
     
       22. A method of measuring the angle of relative wind with respect to an aircraft's wing chord for determining AOA, the method comprising: 
       allowing airflow between top and bottom surfaces on the aircraft via an enclosed airflow path; and  
       measuring the rate of such airflow.